A dog’s bark may be worse than his bite, but most of us would rather not find out one way or the other. Growling, baring teeth, snarling, snapping, and biting are all aggressive behaviorsâ€”but dog aggression includes any behavior meant to intimidate or harm a person or another animal. Although these messages are among the handful of communication tools available to dogs, they’re generally unacceptable to humans. Because humans and dogs have different communication systems, misunderstandings can occur between the two species.

But from a dog’s perspective, there’s always a reason for aggressive behavior. A person may intend to be friendly, but a dog may perceive that person’s behavior as threatening or intimidating. Dogs aren’t being schizophrenic, psychotic, crazy, or necessarily “vicious” when displaying aggressive behavior.

Types of Aggression

Fear-Motivated Aggression: Fear-motivated aggression is a defensive reaction and occurs when a dog believes he is in danger of being harmed. Remember that it’s your dog’s perception of the situation, not your actual intent, which determines your dog’s response. For example, you may raise your arm to throw a ball, but your dog may bite you because he believes he’s protecting himself from being hit. A dog may also be fearfully aggressive when approached by other dogs. [Most aggression that we see is based on fear. Check out fearfuldogs.com for more resources on fear.]

Protective, Territorial, and Possessive Aggression: Protective, territorial, and possessive aggression are all very similar, and involve the defense of valuable resources. Territorial aggression is usually associated with defense of property, and that “territory” may extend well past the boundaries of your yard. For example, if you regularly walk your dog around the neighborhood and allow him to urine-mark, he may think his territory includes the entire block. Protective aggression usually refers to aggression directed toward people or animals whom a dog perceives as threats to his family, or pack. Dogs become possessively aggressive when defending their food, toys, or other valued objects, including items as peculiar as tissues stolen from the trash. (Click here for an article on resource guarding).

Redirected Aggression: This is a relatively common type of aggression but one that is often misunderstood by pet owners. If a dog is somehow provoked by a person or animal he is unable to attack, he may redirect this aggression onto someone else. For example, two family dogs may become excited, and bark and growl in response to another dog passing through the front yard; or two dogs confined behind a fence may turn and attack each other because they
can’t attack an intruder. Predation is usually considered to be a unique kind of aggressive behavior because it’s motivated by the intent to obtain food, and not primarily by the intent to harm or intimidate.

Dominance Aggression: Dominance aggression is motivated by a challenge to a dog’s social status or to his control of a social interaction. Dogs are social animals and may view their human families as their social group or “pack.” Based on the outcomes of social challenges among group members, a dominance hierarchy or “pecking order” is established.

[Ahimsa note: Not all scientists agree that dogs have a pack structure, or that if they do, that it includes the humans in the household. I believe pack structure of dogs does not influence as much as people think, and that it is very fluid. Your dogs may be have one order inside and a different order outside. It may be different for different resources. Dominance is not a personality trait of a dog. It describes the relationship of a dog with another dog or a human. If a dog is dominant with respect to another dog, then she has more access to valued resources.

Your role, as the human in the household, should be to dole out resources. You are the keeper of the resources, which therefore makes you the Alpha dog, if you like that term (I don’t). The canines in the household should be informed that the first 20 highest rankings have been taken by you and your human companions and they get to arrange themselves in the last few. There’s much less reason to fight over 21st and 22nd place than 1st and 2nd.

How do you do that? For starters, you don’t follow the old advice of giving treats, food, and attention to the top dog. That only reinforces your dogs for being bullies. Instead, teach your dogs to Say Please for the fun things in life. Teach them that dogs in your household get
wonderful things by being polite and nothing by being pushy with each other or with your human family.]

Individual Variation

The likelihood of a dog to show aggressive behavior in any particular situation varies markedly from dog to dog. Some dogs tend to respond aggressively with very little stimulation. Others may be subjected to all kinds of threatening stimuli and events
and yet never attempt to bite.

The difference in the threshold prompting aggressive behavior is influenced by both environmental and genetic factors. If this threshold is low, a dog will be more likely to bite.
Raising the threshold makes a dog less likely to respond aggressively. This threshold can be raised using behavior modification techniques, but the potential for change is influenced by a dog’s gender, age, breed, general temperament, and the way in which the behavior modification techniques are chosen and implemented.

Because working with aggressive dogs can be potentially dangerous, behavior modification techniques should only be attempted by, or under the guidance of, an experienced animal behavior professional who understands animal learning theory and behavior.

What You Can Do:

First, check with your veterinarian to rule out medical causes for the aggressive behavior.

Seek professional advice. An aggression problem will not go away by itself. Working with aggression problems requires in-home [and on the road] help from an animal behavior specialist.

Take precautions. Your first priority is to keep people and other animals safe. Supervise, confine, and/or restrict your dog’s activities until you can obtain professional guidance. You are liable for your dog’s behavior. If you must take your dog out in public, consider a cage-type muzzle as a temporary precaution, and remember that some dogs are clever enough to get a muzzle off. [Ahimsa note: Introduce your dog to the muzzle,
with lots of praise and treats, days or weeks before you need to use it.]

Avoid exposing your dog to situations where he is more likely to show aggression. You may need to keep him confined to a safe room and limit his contact with people.

If your dog is possessive of toys or treats, or territorial in certain locations, prevent ccess and you’ll prevent the problem. In an emergency, bribe him with something better than what he has. For example, if he steals your shoe, trade him the shoe for a piece of chicken. [More on Resource Guarding.]

Spay or neuter your dog. Intact dogs are more likely to display dominance, territorial, and protective aggressive behavior. [Applies more to males. They are also more likely to be attacked by other dogs.]

What NOT to Do:

Punishment won’t help and, in fact, will often make the problem worse. If the aggression is motivated by fear, punishment will make your dog more fearful, and therefore more
aggressive. Attempting to punish or dominate a dominantly aggressive dog [using “alpha rolls”, etc.] may actually lead him to escalate his behavior to retain his dominant position. This is likely to result in a bite or a severe attack. Punishing territorial, possessive, or protective aggression is likely to elicit additional defensive aggression.

Don’t encourage aggressive behavior. Playing wrestling games encourages your dog to attempt to “best” you or “win” over you, which can lead to a dominance aggression problem. When dogs are encouraged to “go get ’em” or to bark and dash about in response to outside noises or the approach of a person, territorial and protective aggressive behavior may result.

No guarantee is stated or implied in this article and if you follow any of the advice in it, you do so at your own risk. If you ever feel that you, your dog, or others are at risk because of your dog, we strongly encourage you to seek the services of a professional dog trainer.